<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        div {
            width: 200px;
            height: 200px;
            color: blue;
        }
    </style>
</head>
<body>
<div class="hello">你好，我是div</div>
<ul>
    <li>1</li>
    <li>2</li>
    <li>3</li>
    <li>4</li>
    <li>5</li>
</ul>
<input type="button" value="显示" id="show"/>
<input type="button" value="隐藏" id="hide"/>
<input type="button" value="toggle" id="toggle"/>
<div style="width: 20px;height: 20px;background-color: red;" id="haha"></div>


<div><span>123</span></div>
<div><span>1234</span></div>
<div><span>1235</span></div>
<div><span>1236</span></div>
<div><span>1237</span></div>
</body>
<script src="myJquery2.2.js"></script>
<script>

</script>
<script>
    console.log($('li').get(-1));

    console.log($('li').first()[0].innerText);
    console.log($('li').last());

    console.log($('li').eq(3));


    console.log($('div').find('span'));

    console.log(jQuery.fn.init());

</script>
</html>